Frequency tunable zeroth-order resonant antenna by using RF MEMS on slotted ground plane

In this paper, a frequency tunable zeroth-order resonant (ZOR) antenna has been implemented. The ZOR characteristics of the proposed antenna is realized by using the composite right-and left-handed (CRLH) transmission line which is realized by way of a rectangular slot on the ground plane of mushroom structured antenna in order to minimize the antenna size. In addition, the RF MEMS switches are introduced on the slotted ground plane for frequency tuning capability. Depending on the on and off states of the tunable device on the slotted ground plane, a shunt inductance value of the CRLH transmission line is changed and its resonant frequency becomes tunable. From the experimental results, the resonant frequency of the proposed antenna is changed from 4.92 GHz to 2.96 GHz. Additionally, the proposed antenna´s size is reduced by 94.24 % compared with the conventional half-wavelength patch antenna.